Tracking a person's gaze direction via a computing system may find use in many applications, including but not limited to human-computer interactions, visual attention analysis, and assistive technologies for people with disabilities. For example, a gaze direction of a person may be used to determine a location at which the person's gaze intersects a graphical user interface of a computing system. The determined location then may be used as an input signal for interacting with the graphical user interface.